For emergency lighting systems, operating devices (ballasts) are used for the operation of connected lights through an additional power supply, which ensures the operation of the connected lights for a predetermined period of time even in the event of a mains power failure. The power supply is maintained in the event of failure of the primary mains power supply by means of energy stored in accumulators for a rated operating time, in order, for example, to allow persons to leave a building with a specific illumination for the rated operating time.
The functionality of the emergency lighting must be checked at regular intervals as part of function tests, as well as continuously during operation as part of self-tests. Such a function test is triggered, for example, by actuating a test switch (test button) connected externally to an emergency lighting operating device. The connection of the test switch to the emergency light operating device is two-wire, often by means of plug connectors, and therefore requires two externally accessible connection options to the emergency light operating device.
The operating state (status) of an emergency lighting system is usually signaled externally. To this end, a green light emitting diode (LED) signals that the emergency lighting system is operational, while a detected fault in the emergency lighting system is signaled by a red LED. Conventional operating devices, therefore, have at least two additional external connections for the LEDs for the status display.
Thus, emergency lighting operating devices have at least six external connections, each of which requires corresponding space in a housing, and corresponding cabling related to the installation of an emergency lighting system.